The present invention relates to the measurement of ball pen writing quality, and more particularly to the employment of a computerized/image system for analysis of ball point pen writing.
In the manufacture of ball point pens, writing quality generally depends on the maintenance of relatively tight tolerances during the precision manufacturing processes. Presently the test for manufacturing process quality is achieved by having a writing sample prepared by a cam driven machine, after which a human grader rates the sample and the grader assigns values which range from acceptable to most severe for each of the rated categories. The traces are visually examined for line quality which may generally be divided into the three measurements of ink laydown, degree of blobbing and degree of line inconsistency. Ink laydown, which is generally designated as the milligrams of ink dispensed per 185 feet of written line, is now measured periodically in a manual fashion after pen assembly to give an indication of the tolerances achieved in the point making operation.
Additionally, in the area of research and development, while visual examination as set forth above has proved to be somewhat. successful, as product development becomes increasingly more customer driven, the ability to cost effectively determine consumers perception of writing quality becomes more important and there is a need to provide a method of writing analysis which is more comprehensive, repeatable and cost effective to provide useful correlation between a sample and the consumers' perception of writing quality.
With the advent of advanced fully featured computer vision/image analysis capability-available at moderate cost for PC based systems, the number of applications having favorable cost benefit ratios in research process development and manufacturing has increased. Such applications are capable of providing improvements in research efficiencies, (for instance the rapid determination of number of facial hairs per square inch with a quantitative data on hair size and shape), in manufacturing efficiency, (such as rejection of fewer good parts and assemblies), and in any other situation in which analysis of visual images is important. The area of writing quality metrics therefore, is one having a great potential for such application.
It is therefore an object of the present invention to improve the analysis of ball pen writing quality by the application of vision system technology.
A further object of the invention is to replace the relatively subjective human sample grading of a ball point writing sample with a relatively objective machine grading.
Still a further objective of the invention is to employ a histogram comprising a pixel image of a writing sample to measure the rate of ink laydown, degree of blobbing, and degree of line inconsistency enabling comparison with pre-established values corresponding to qualities.